Out-of-bounds read in PPP - #VU151453
Published: September 19, 2026
Vulnerability identifier: #VU151453
CSH Severity: Low
CVSS v4: 2.3 [CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-125
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in the chapms_make_response and chapms2_make_response functions in pppd/chap_ms.c when handling a CHAP challenge with an undersized Challenge-Value-Size field. A remote attacker can send a specially crafted CHAP challenge to disclose sensitive information.
MS-CHAP or MS-CHAPv2 support must be enabled, and exploitation requires control of or a man-in-the-middle position for the PPP server.
Affected software
PPP
Remediation
Install security update from vendor's website.
PPP - update to 2.5.4